Category:Dc: Difference between revisions

Dc
This programming language may be used to instruct a computer to perform a task.

Execution method:	Interpreted
Type checking:	Dynamic
See Also:	Dc on the HOPL

Listed below are all of the tasks on Rosetta Code which have been solved using Dc.

dc is the unix desktop calculator. It uses a reverse polish notation and is turing complete.

Quick reference

Commands in AT&T dc

number      : push a number (0-9A-F digits, _ negative, . radix point)
[...]       : push a string
+ - * / % ^ : arithmetic operations: add sub mul div mod pow
v           : square root
c           : clear stack
d           : duplicate top of the stack
f           : show stack
p           : print value with a newline, leave it on the stack
P           : print string, or print number as ASCII string
sx          : store to register x
lx          : load from register x
Sx          : push to register x
Lx          : pop register x
a b :x      : store x[b] = a (x is register)
a ;x        : retrieve x[b]
<x >x =x    : compare top 2 values: if true, then execute register x
!>x !<x !=x :   (example: 5 2 <A executes register A if 2 < 5)
!           : shell command
q           : quit, or break 2 execution levels
n Q         : break n execution levels
i           : set input radix from top of stack
I           : get current input base, push it on stack
o           : set output radix from top of stack
O           : get current output base, push it on stack
k           : set scale factor
K           : get current scale factor
x           : execute a string of dc commands
X           : count decimal digits after decimal point
z           : count elements on the stack
Z           : count all decimal digits in number, or characters in string
?           : read and execute one line of input
Y           : debug information

Extensions in both GNU dc and OpenBSD dc

a           : print ASCII character
n           : print value without a newline
~           : divmod: division and remainder
r           : reverse (swap) the top two elements
#           : comment

Extension in GNU dc

|           : arithmetic - modular exponentiation

Extensions in OpenBSD dc

n J         : break n execution levels, then jump to next M
M           : mark for the J command
a N         : boolean not: push 1 if a == 0, else push 0
R           : pop and discard top of the stack
<xey >xey   : comparisons with an else branch: if true,
=xey !<xey  :   then execute register x
!>xey !=xey :   else execute register y
a b G       : equality: push 1 if b == a, else push 0
a b (       : less than: push 1 if b < a, else push 0